Rhabdomyosarcoma (RMS) is a cancer that develops from the cells that normally develop into skeletal muscles. RMS commonly occurs in the head and neck, urinary and reproductive organs, arms and legs or chest and abdomen. There are several types of RMS including: embryonal rhabdomyosarcoma, alveolar rhabdomyosarcoma, anaplastic rhabdomyosarcoma and undifferentiated sarcoma.